1. Field of the Invention
The present invention relates to a semiconductor integrated circuit, and particularly to a circuit having a regulator.
2. Description of Related Art
In recent years, operating voltage has been decreasing with miniaturization of devices. On the other hand, electrical power consumption is increasing due to an increase in circuit size and faster circuit speed. In such a semiconductor integrated circuit, an internal power supply voltage is generated from an external power supply voltage. The internal voltage is supplied to the internal circuit.
For such a technique, techniques disclosed in Japanese Unexamined Patent Application Publication No. 2004-22647 and Japanese Unexamined Patent Application Publication No. 2003-243538 are known. In the techniques, a plurality of MOS transistors are connected between a line for transmitting an external power supply voltage and a line for supplying an internal power supply voltage. A reference potential generated by a control circuit is supplied to gates of the plurality of MOS transistors. The reference potential is changed so as to adjust the internal power supply voltage to a specified internal power supply voltage.
In a conventional technique, a standard potential is created by a control circuit monitoring a dummy circuit or monitoring an internal voltage output by a MOS transistor. With such configuration, it is often difficult to adjust an entire internal power supply voltage to a desired value with a fluctuation in the dummy circuit to monitor or the voltage point to monitor.
Thus a conventional technique has no consideration over a spot to monitor the internal power supply voltage. Accordingly it has now been discovered that it is often difficult to adjust the internal power supply voltage close to a desired value.